1. Field of Invention
This invention relates generally to irrigation systems and more particularly to traveling type irrigation systems which wind a flexible water supply pipe to the sprinkler gun carriage around a reel to pull the sprinkler gun toward the reel as water is discharged from the sprinkler gun.
2. Discussion of Background Art
Irrigation systems using a non-collapsible flexible water supply pipe from a reel unit to the sprinkler gun carriage so that the pipe can be wound around a reel on the reel unit to tow the sprinkler gun carriage over the ground toward the reel unit have gained widespread acceptance because of their ability to irrigate areas with widely varying configurations and because they are easily moved from location to location.
One of the biggest problems associated with these prior art irrigation systems is the control of the speed of movement of the sprinkler gun carriage toward the reel unit so as uniformly to distribute the water over the entire length of the irrigation pattern. This is due primarily to the buildup of the hose on the reel as it is wound varying the speed of movement of the sprinkler gun carriage over the length of the run. Attempts have been made to compensate for this variance by incrementally changing the speed of rotation of the reel as each new layer of pipe is wrapped around the reel. Because the effective distance of the hose from the center of rotation of the reel may vary within a layer, or the layers may not increase by fixed increments, such attempts have not adequately controlled the speed of movement of the sprinkler gun carriage to assure uniform water distribution.
Another problem associated with the prior art irrigation systems is that no means was provided to shut off the water supply in the end of an irrigation run and they thus relied on the operator to keep checking the system to manually turn off the water supply at the end of the run or in the event a malfunction caused the carriage unit to stop during the run. Further, many of these prior art irrigation systems required that the carriage unit be disconnected from the reel unit at the end of a run and reconnected to the reel unit at the beginning of a run thereby requiring additional setup time between runs. These prior art irrigation systems further had no means to automatically shut down the system in the event of system malfunction so that damage to the various components of the system frequently resulted when a malfunction occurred. Also, these prior art irrigation systems required that the operator return to the system after it was connected to the water supply to start the system at the beginning of the run. No provision was made in these prior art systems to detect and display the actual speed of movement of the sprinkler gun carriage so that a manual measuring and timing operation was required to determine this speed.